On Thu, Mar 20, 2008 at 03:20:10AM -0700, Andrew Morton wrote:
> > > I also suspect that CTQ has not been set up correctly on this
> > > kernel, because:
> > >
> > > $ cat /sys/block/sdb/device/queue_depth
> > > 3
> > > $ ls -l /sys/block/sdb/device/queue_depth
> > > -r--r--r-- 1 root root 0 Mar 20 09:59 /sys/block/sdb/device/queue_depth
> > > $
> > >
> > > It appears to be hard coded to 3 and can't be changed....
> >
> > That's a bug in the qla1280 driver. I thought that had gotten fixed.
> > It's looking at the wrong mailbox register after setting device parameters.
>
> Was there a patch anywhere?
Promised patch...
The qla1280 driver was ANDing the output value of mailbox register
0 with (1 << target-number) to determine whether to enable queueing
on the target in question.
But mailbox register 0 has the status code for the mailbox command
(in this case, Set Target Parameters). Potential values are:
/*
* ISP mailbox command complete status codes
*/
#define MBS_CMD_CMP 0x4000 /* Command Complete. */
#define MBS_INV_CMD 0x4001 /* Invalid Command. */
#define MBS_HOST_INF_ERR 0x4002 /* Host Interface Error. */
#define MBS_TEST_FAILED 0x4003 /* Test Failed. */
#define MBS_CMD_ERR 0x4005 /* Command Error. */
#define MBS_CMD_PARAM_ERR 0x4006 /* Command Parameter Error. */
So clearly that is in error. I can't think what the author of that
line was looking for in a mailbox register, so I just eliminated the
AND. flag is used later in the function, and I think that the later
usage was also wrong, though it was used to set values that aren't
used. Oh well, an overhaul of this driver is not what I want to do
now -- just a bugfix.
After the fix, I found that my disks were getting a queue depth of
255, which is far too many. Most SCSI disks are limited to 32 or
64. In any case, there's no point, queueing up a bunch of commands
to the adapter that will just result in queue full or starve other
targets from being issued commands due to running out of internal
memory. So I dropped default queue depth to 32 (from which 1 is
subtracted elsewhere, giving net of 31).
I tested with a Seagate ST336753LC, and results look good, so
I'm satisfied with this patch.
Signed-off-by: Jeremy Higdon <jeremy@xxxxxxx>
---
--- a/drivers/scsi/qla1280.c 2008-05-03 11:59:44.000000000 -0700
+++ b/drivers/scsi/qla1280.c 2008-05-10 21:32:23.451341969 -0700
@@ -2007,7 +2007,7 @@ qla1280_set_defaults(struct scsi_qla_hos
nv->bus[bus].config_2.req_ack_active_negation = 1;
nv->bus[bus].config_2.data_line_active_negation = 1;
nv->bus[bus].selection_timeout = 250;
- nv->bus[bus].max_queue_depth = 256;
+ nv->bus[bus].max_queue_depth = 32;
if (IS_ISP1040(ha)) {
nv->bus[bus].bus_reset_delay = 3;
@@ -2051,7 +2051,7 @@ qla1280_config_target(struct scsi_qla_ho
status = qla1280_mailbox_command(ha, 0x0f, mb);
/* Save Tag queuing enable flag. */
- flag = (BIT_0 << target) & mb[0];
+ flag = (BIT_0 << target);
if (nv->bus[bus].target[target].parameter.tag_queuing)
ha->bus_settings[bus].qtag_enables |= flag;
--
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